Blog Activity 4

1.     Run the Build an Atom simulation and build a neutral lithium atom and a neutral boron atom. Take a picture, or a screen shot, of these two atoms and place them on your blog. List the number of protons, neutrons, and electrons for each. Also look up and post the density for each of the elements on your blog.

Neutral lithium atom: 3 protons, 3 neutrons, 3 electrons   Density:  0.534 g/cm-3 

    Neutral boron atom: 5 protons, 6 neutrons, 5 electrons     Density: 2.34 g/cm-3 

2.     Define density and the equation for density.

         Density is the quantity of mass per unit volume. The equation for density is density = mass/volume.

3.     Run the Density simulation and complete one activity of the prepared teaching ideas and post the results on your blog. The activity you choose should be one of the student intended activities.

Density

Introduction:  Density is a physical property of matter that is calculated by dividing the mass of an object by its volume.  Volume can be computed for a regular object by multiplying length x width x height.  Another way to compute volume is by submerging an object into a liquid.  You must record the starting volume of the liquid and the final volume after the object has been submerged.  Then subtract the starting volume from the final volume. 

Procedure:

• Open the internet browser and enter the address:  http://phet.colorado.edu
• Click on “Play with Sims” and select “Chemistry” from the menu on the left.
• Open the “Density” Simulation and select “Run Now”

Objectives:

• Describe how the concept of density relates to an object's mass and volume.
• Explain how objects of similar mass can have differing volume, and how objects of similar volume can have differing mass.
• Measure the volume of an object by observing the amount of fluid it displaces.
• Identify an unknown material by calculating its density and comparing to a table of known densities.

Investigate:

1.       On the Blocks menu (top right) select Same Mass. 

2.      One at a time, take a block, lower it into the liquid, and record its volume.  If it floats, you will need to hold it under the water to record its volume.  Then compute each block’s density.

  Blue:      mass                      5 kg                               Density:    1 kg/L
          volume                     5 L

Yellow     mass                5kg                                 Density:  .5 kg/L             
              Volume             10 L

Green       mass                  5kg                                Density:    2 kg/L
               Volume               2.5 L

Red          mass                  5kg                              Density:  4 kg/L

               Volume             1.25 L

1.      Repeat for Same Volume.

Blue:     mass                        6.00 kg                      Density:     1.2 kg/L
      volume                     5 L

Yellow    mass                  8.00 kg                     Density:   1.6 kg/L

             volume                    5L

Green    mass                   4.00 kg                      Density:   .8 kg/L

            volume                    5L

Red      mass                2.00 kg                       Density:   .4 kg/L

           Volume                     5L

2.     Repeat for Same Density

Blue:    mass                        3.00 kg                       Density:  .8 kg/L
    volume                       3.75 L

Yellow   mass                       4.00 kg                      Density:   .8 kg/L

             volume                        5 L

Green    mass                    2.00 kg                       Density:   .8 kg/L

             volume                    2.50 L

Red      mass                  1.00 kg                       Density:  .8 kg/L

            volume                    1.25 L

 

3.      Repeat for Mystery.  This time  you will also have to take the mass of each object.  After computing the density,  select Show Table and identify each object.
                                                                                                             IDENTIFICATION

A:     mass             65.14 kg         Density:  19.3 kg/L             Gold
     volume              3.38 L

B     mass             .64 kg             Density:  .64 kg/L                 Apple

       Volume            1 L

 

C    mass               4.08 kg         Density:    .70 kg/L                           Gasoline

     volume             5.83 L

 

D   mass               3.10 kg           Density .92 kg/L                                  Ice
    volume              3.38 L

E    mass              3.53 kg          Density:  3.53 kg/L                        Diamond

    volume              1 L

1.     Complete the Mystery Blocks activity on the Density simulation. Post on your blog the data you collected (mass, volume, and density) and the identification of the material and the known density.
                                                                                                            IDENTIFICATION

A:   mass             65.14 kg             Density:   19.3 kg/L             Gold
 volume           3.38 L

B   mass              .64 kg                 Density: .64 kg/L                  Apple

     Volume            1 L

 

C  mass              4.08 kg                Density:  .70 kg/L                             Gasoline

    volume           5.83 L

 

D  mass            3.10 kg                 Density: .92 kg/L                                  Ice

    volume          3.38 L

E  mass             3.53 kg                Density:  3.53 kg/L                         Diamond

    volume             1 L

2.     Identify and post on your blog the Science Standards that could be met through these activities.

 A.4.2  When faced with a science-related problem, decide what evidence, models, or explanations previously studied can be used to better understand what is happening now

A.8.8. Use the themes of evolution, equilibrium, and energy to predict future events or changes in the natural world

C.4.4 Use simple science equipment safely and effectively, including rulers, balances, graduated cylinders, hand lenses, thermometers, and computers, to collect data relevant to questions and investigations

C.8.1 Identify* questions they can investigate* using resources and equipment they have available

C.8.2 Identify* data and locate sources of information including their own records to answer the questions being investigated

C.12.5 Use the explanations* and models* found in the earth and space, life and environmental, and physical sciences to develop likely explanations* for the results of their investigations*

D.4.1 Understand that objects are made of more than one substance, by observing, describing and measuring the properties of earth materials, including properties of size, weight, shape, color, temperature, and the ability to react with other substances

      D.4.2 Group and/or classify objects and substances based on the properties of earth materials